JP2019104396A - tire - Google Patents

Abstract

To widen the range of expression of a decorative part including an area where projections are formed in a tire.SOLUTION: A tire comprises: a decorative part 14 formed at a tire outer surface and having a base surface 30; and a low brightness area 18 as a pattern area in which a plurality of first asterisk projections 34 and second asterisk projections 36 are formed at the decorative part 14, projected from the base surface 30 in intervals that are 0.1 mm or more and 1.0 mm or less, and in heights that are 0.1 mm or more and 1.0 mm or less. The pattern area 18 includes a taper area 48 where heights of the first asterisk projections 34 and the second asterisk projections 36 that are adjacently arranged are progressively reduced.SELECTED DRAWING: Figure 4

Description

  The present invention relates to a tire having a projection formed on the outer surface.

  Heretofore, it has been practiced to form minute projections on the side portions of a tire to form a pattern region having contrast. For example, Patent Document 1 discloses a technique for exhibiting a large contrast on the side portion of a tire by a plurality of projections formed over the entire pattern area.

International Publication No. 2012/131089

  The decorative portion of the side portion of the tire has a region where a protrusion is formed. The lightness of this one area is lower than that of the other area where the light is reflected as it is by controlling the reflection of the light by the projections. However, the width for expressing the decorative portion on which the projections are formed is limited if the area where the projections are formed is lowered with the same lightness as a whole.

  An object of the present invention is to widen the expression of a decorative part having a region where a projection is formed in a tire.

  The tire according to claim 1 is formed on the outer surface of the tire, and is provided on a decorative portion having a base surface, and the decorative portion, and protrudes from the base surface and the distance is greater than 0.1 mm 1 And a pattern area in which a plurality of protrusions each having a height of 0.1 mm or more and 1.0 mm or less are formed. A tapering area is provided in which the heights of the plurality of projections disposed adjacent to each other gradually taper off.

  According to the tire of claim 1, a pattern area is formed in the decorative portion of the outer surface of the tire. In this pattern area, while protruding from the base surface, the distance is greater than 0.1 mm and not more than 1.0 mm, and the protrusion height is not less than 0.1 mm. A plurality of projections set to 0 [mm] or less are formed.

  As a result, the light incident on the pattern area is repeatedly reflected on the opposite side surfaces of the projections while being attenuated and reflected to the outside, so that the pattern area corresponds to the other area of the outer surface of the tire where the projections are not formed (smooth Lightness is lower than that of

  The pattern area is provided with a gradually decreasing area in which the heights of the plurality of projections disposed adjacent to each other are gradually reduced. As described above, light incident on the pattern area is attenuated while repeatedly reflecting on the opposite side surfaces of the protrusions, but when the height of the protrusions is low, light attenuation is reduced and much of the light reflected to the outside of the tire is large. The brightness is high.

  Since the heights of the protrusions gradually decrease in the gradual reduction region, the light reflected to the outside of the tire in the gradual reduction regions increases from the high portion to the low portion of the protrusions and appears to be gradually brighter. That is, in the gradual reduction area, gradation is applied to the lightness, and the width of expression of the decorative portion having the area where the projection is formed in the tire can be expanded as compared with the case where the lightness is constant.

  In the tire according to the second aspect of the present invention, in the tire according to the first aspect, the gradually decreasing area is provided with a plurality of the protrusions whose height from the base surface is constant, and from the base surface The height from the bottom raising portion to the top of the protrusion gradually decreases because the bottom raising portion provided with a gradually increasing portion whose height gradually increases is provided straddling a plurality of the protrusions.

  In the tire according to the second aspect of the present invention, the plurality of projections are provided with the raised portion provided with the gradually increasing portion whose height from the base surface is gradually increased after providing the plurality of projections whose height from the base surface is made constant. By providing them straddling, it is possible to realize a configuration in which the height from the bottom raising portion to the top of the protrusion is gradually reduced.

  The invention according to claim 3 is the tire according to claim 2, in which the two raised portions in the bottom raising portion are connected in opposite directions to each other.

In the tire according to claim 3, since the bottom raising portion has the two ascending portions connected in the opposite directions to each other, the height of the bottom raising portion gradually increases from one side to the other side. And then gradually decrease.
Therefore, in the portion where the bottom raising portion according to claim 3 is disposed, the light reflected to the outside of the tire gradually decreases and then gradually decreases. In other words, the width for expressing the decorative part can be further expanded as compared with the case where it looks gradually darkened after gradually brightening, and gradually brightens and suddenly appears black.

  The invention according to a fourth aspect is the tire according to the second or third aspect, wherein the portion where the height of the bottom raising portion changes is formed by a curve which is convex toward the base surface.

Since the portion where the height of the bottom raising portion changes is formed by a curved surface that is convex toward the base surface, the inclination angle of the bottom raising portion (curved surface portion) with respect to the base surface gradually increases from the foot portion toward the top Because of this, the change in the amount of light reflected to the outside of the tire is relatively small at the foot and relatively large near the top.
Therefore, compared with the case where it is formed by a curved surface or a plane which is concave toward the base portion, it is possible to make the appearance and the portion where the height of the bottom raising portion becomes maximum bright and clear. In other words, since the change in brightness is small near the bottom of the bottom raising portion and the change in brightness is large near the top, a portion where the height of the bottom raising portion becomes maximum becomes noticeable. Thereby, the width of expression of the decoration part can be further expanded.

  The invention according to claim 5 is the tire according to any one of claims 2 to 4, wherein the base surface is a bottom portion of a recess formed toward the tire inner side than the outer surface, The raised bottom portion is formed such that the top portion does not protrude from the outer surface to the outside of the tire.

  In the tire according to claim 5, since the top of the raised bottom portion is formed so as not to protrude from the outer surface of the tire to the outside of the tire, the raised portion does not easily hit against the flow of air flowing along the tire surface during traveling. The aerodynamic effect can be improved.

  The invention according to a sixth aspect is the tire according to any one of the second to fourth aspects, wherein the base surface is a bottom portion of a recess formed toward the inner side of the tire than the outer surface, The projection is formed such that the top does not protrude from the outer surface to the tire outer side.

  In the tire according to claim 5, since the top of the projection is formed so as not to protrude from the outer surface of the tire to the outer side of the tire, the projection becomes difficult to hit against the flow of air flowing along the tire surface during traveling. Aerodynamic effects can be improved.

  The invention according to claim 7 is the tire according to any one of claims 1 to 6, wherein the height of the protrusion measured from the base surface is constant in the gradual decrease area.

  By making the height of the projections measured from the base surface constant, the processing depth of the recesses formed in the mold for forming the projections can be made constant, and the pattern area other than the gradual reduction area is maintained at a constant blackness can do.

  In the tire according to an eighth aspect of the present invention, in the tire according to the second aspect, three or more types of the protrusions having different heights from the bottom raising portion are provided in the gradually decreasing area.

  In a tire provided with a raised bottom portion projecting from the base surface in the gradual reduction area, by providing three or more types of protrusions having different heights from the raised bottom portion, it is possible to obtain smooth gradation.

  In addition, in the case where the height of the protrusion is made different by providing the raised portion, if two protrusions having different heights are provided, the change of the height of the raised portion per unit length becomes too large, In the gradual reduction area, a large level difference in which stress tends to concentrate is generated, and there is a concern that a crack may be generated from the level difference portion. On the other hand, if three or more types of protrusions having different heights are provided, the change in height of the raised portion per unit length becomes smaller in the gradually decreasing region, stress concentration is relaxed, and cracks are less likely to occur. Become.

  According to the present invention, it is possible to widen the expression of the decorative portion in which the projection is formed in the tire.

(A) is a side view of a tire according to a first embodiment of the present invention, and (B) is an explanatory view showing a relationship between a bottom-up protrusion and a lightness of a gradation area provided in a low lightness area of a decorative portion. , (C) is a perspective view of the bottom raising projection. It is the top view which showed the low brightness area of the decoration part of the tire concerning a 1st embodiment of the present invention. It is the enlarged plan view which showed the processus | protrusion formed in the low-lightness area | region of the decoration part of the tire which concerns on 1st Embodiment of this invention. (A) is a cross-sectional view showing a first asterisk protrusion formed in a low lightness area of the decorative portion of the tire according to the first embodiment of the present invention, and (A) is a sectional view showing the first asterisked area formed in the low lightness area It is sectional drawing which showed two asterisk processus | protrusions. It is the top view which showed the low brightness area formed in the decoration part of the tire concerning a 2nd embodiment of the present invention. (A) is a cross-sectional view showing a low brightness area of a decorative portion of a tire according to a second embodiment of the present invention, and (B) is a cross-sectional view of a rib-like protrusion formed in the low brightness area. (A)-(C) is a sectional view of a bottom raising projection concerning other embodiments. It is a perspective view of the tread which showed the decoration part of the tire concerning a 3rd embodiment of the present invention. It is sectional drawing of the low brightness area | region of the tire concerning other embodiment.

First Embodiment
An example of a tire according to a first embodiment of the present invention will be described according to FIGS. 1 to 5. In addition, arrow C shown in a figure shows a tire peripheral direction, and arrow R shows a tire radial direction.

  As shown in FIG. 1A, a decorative portion 14 is formed on the tire side portion 12 of the tire 10. Although the decoration part 14 of this embodiment is made into circular arc shape seeing from the axial direction of the tire 10, it may be annular ring shape continuous in the circumferential direction.

  Furthermore, in the area other than the decorative part 14 in the tire side part 12, the smooth base surface 30 (see FIG. 4) recessed with a fixed dimension with respect to the other area 20 where projections and the like described later are not formed It is formed in the part 14. In the present embodiment, the base surface 30 is recessed by 0.45 mm with respect to the other area 20 of the tire side portion 12 (see FIG. 4). The base surface 30 of the present embodiment has the same surface roughness as the other regions 20.

  Furthermore, in the decorative portion 14, a low brightness area 18 which has a low brightness compared to the other areas 20 and looks black is entirely formed. The low lightness area 18 is an example of a pattern area.

  In the mold (mold) for molding the tire 10, the low lightness region 18 is formed by providing unevenness in a portion corresponding to the low lightness region 18. It is preferable that the low brightness region 18 be disposed in the tire side portion 12 from the viewpoint of visibility in a state where the tire 10 is mounted on a vehicle.

(Low lightness area 18)
As shown in FIGS. 2 to 3, the low lightness region 18 has a plurality of first asterisk protrusions 34 protruding from the base surface 30 and a plurality of second asterisk protrusions 36. The first asterisk protrusions 34 and the second asterisk protrusions 36 are alternately arranged in the tire circumferential direction and the tire radial direction. The first asterisk protrusion 34 and the second asterisk protrusion 36 are an example of a protrusion.

[First asterisk projection 34]
As shown in FIG. 3, when viewed from the direction orthogonal to the base surface 30 (the direction of the rotation axis of the tire 10), the first asterisk protrusions 34 extend in different directions from the center O1 as the base point. It is comprised by one extension part 35A-1, 35A-2, 2nd extension part 35B-1, 35B-2, and 3rd extension part 35C-1, 35C-2. Hereinafter, these six extension parts are collectively called "extension part 34E." Then, a linear shape bent at the center O1 is configured by one extension part 34E and the other extension parts 34E (except those extending in opposite directions from the center O1).

  The first extending portion 35A-1 and the first extending portion 35A-2 extend in opposite directions from the center O1, and the first extending portion 35A-1 and the first extending portion 35A-2 A linear and continuous shape is configured. The first extending portion 35A-1 extends outward from the center O1 in the tire radial direction, and the first extending portion 35A-2 extends inward from the center O1 in the tire radial direction. And 1st extension part 35A-1 and 1st extension part 35A-2 are made into the same length. Hereinafter, 1st extension part 35A-1 and 1st extension part 35A-2 are collectively called "1st extension part 35A."

  The second extending portion 35B-1 and the second extending portion 35B-2 extend in opposite directions from the center O1, and the second extending portion 35B-1 and the second extending portion 35B-2 A linear and continuous shape is configured. In the second extending portion 35B-1 and the second extending portion 35B-2, the end of one side (left side in the figure) of the tire circumferential direction is compared with the end of the other side (right side in the figure), It is inclined with respect to the tire circumferential direction so as to be located radially outward.

  The second extending portion 35B-1 extends from the center O1 to one side in the tire circumferential direction, and the second extending portion 35B-2 extends from the center O1 to the other side in the tire circumferential direction. The second extending portion 35B-1 is longer than the second extending portion 35B-2. Furthermore, the portion on the tip end side of the second extending portion 35B-2 is curved inward in the tire radial direction. Hereinafter, the second extending portion 35B-1 and the second extending portion 35B-2 will be collectively referred to as a "second extending portion 35B".

  The third extension 35C-1 and the third extension 35C-2 extend from the center O1 in directions opposite to each other, and the third extension 35C-1 and the third extension 35C-2 A linear and continuous shape is configured. The third extended portion 35C-1 and the third extended portion 35C-2 have a tire whose end on one side (left side in the figure) in the tire circumferential direction is compared with the end on the other side (right side in the figure) It is inclined with respect to the tire circumferential direction so as to be located inside in the radial direction.

  The third extension 35C-1 extends from the center O1 to the other side in the tire circumferential direction, and the third extension 35C-2 extends from the center O1 to one side in the tire circumferential direction. The third extension 35C-1 is shorter than the third extension 35C-2. Hereinafter, the third extension 35C-1 and the third extension 35C-2 will be collectively referred to as "third extension 35C".

  The six extending portions 34E form an angle of 60 ° with the adjacent extending portions 34E. In other words, the first asterisk protrusion 34 has a shape in which six extension parts 34E are radially extended from the center O1.

  As shown in FIG. 4A, in the extending portion 34E of the first asterisk protrusion 34, the cross section in the direction orthogonal to the extending direction has a substantially isosceles triangle shape having a flat top surface 34C. . That is, the first asterisk projection 34 has a top surface 34C and a pair of side surfaces 34D. In the present embodiment, the width (W1 in the figure) of the top surface 34C is 0.02 [mm], and the apex angle (D1 in the figure) of the first asterisk protrusion 34 is 26 [degree]. Further, the height (H1 in the figure) of the first asterisk protrusion 34 measured from the base surface 30 is set to a predetermined value of 0.1 mm or more and 1.0 mm or less. . If the height (protrusion height) of the protrusions is less than 0.1 mm, it may be difficult to form the protrusions, and the incident light may be attenuated so that the lightness can not be lowered to the extent that it appears black. There is one (details will be mentioned later) Furthermore, by setting the height of the protrusion to 1.0 mm or less, the difference between the rigidity of the portion of the protrusion and the rigidity of the portion around the protrusion is reduced, and local stress concentration is suppressed. ing.

  The heights of the protrusions and the dimensions (pitch) of the protrusions to be described later in this embodiment can be measured using the one-shot 3D shape measuring machine VR-3000 series of Keyence Corporation as an example. .

[Second asterisk projection 36]
As shown in FIG. 3, the second asterisk projection 36 has the same shape as the first asterisk projection 34. Specifically, when viewed from the direction orthogonal to the base surface 30, the second asterisk projection 36 rotates the first asterisk projection 34 clockwise by 90 degrees around the center O1, and It has a shape obtained by inverting the top and bottom of the first asterisk protrusion 34 rotated 90 degrees around the center O1.

  In the second asterisk projection 36, the first extending portions 35A-1 and 35A-2, the second extending portions 35B-1 and 35B-2, and the third extension portions 35C-1 and 35C- of the first asterisk protrusion 34. 2 and portions corresponding to the center O1 are the first extending portions 37A-1 and 37A-2, the second extending portions 37B-1 and 37B-2, the third extending portions 37C-1 and 37C-2, And called center O2. Hereinafter, the above-mentioned six extension parts are collectively called "extension part 36E."

  As shown in FIG. 4B, a portion of the second asterisk protrusion 36 corresponding to the top surface 34C of the first asterisk protrusion 34 is referred to as a top surface 36C. Furthermore, in the second asterisk protrusion 36, a portion corresponding to the side surface 34D of the first asterisk protrusion 34 is referred to as a side surface 36D. The height H1 and the apex angle D1 of the second asterisk protrusion 36 have the same definition as the first asterisk protrusion 34.

[Others]
As shown in FIGS. 2 and 3, the first and second asterisk protrusions 34 and 36 are alternately disposed in the tire circumferential direction and the tire radial direction, and fill the entire low brightness region 18. ing.

  And each tip of the first extension parts 35A-1 and 35A-2 of the first asterisk protrusion 34 is a second extension part 37B-2 and the third extension of the second asterisk protrusion 36 adjacent in the tire radial direction. It is respectively inserted between the 2nd extension part 37B-1 and the 3rd extension part 37C-2 between the protrusion parts 37C-1. Further, the tip of each of the first extending portions 37A-1 and 37A-2 of the second asterisk protrusion 36 is a second extension portion 35B-1 of the first asterisk protrusion 34 and the third extension adjacent to each other in the tire circumferential direction. It is inserted between the 2nd extension part 35B-2 and the 3rd extension part 35C-1 between the outgoing parts 35C-2.

  Furthermore, the tip of the third extension 35C-1 of the first asterisk protrusion 34, and the second extension 37B of the second asterisk protrusion 36 disposed on the outer side in the tire radial direction with respect to the first asterisk protrusion 34. The tip of 1 is connected. Thus, the connecting portion 34A is formed. Furthermore, the tip of the second extending portion 35B-1 of the first asterisk protrusion 34, and the third extending portion 37C of the second asterisk protrusion 36 disposed on one side in the tire circumferential direction with respect to the first asterisk protrusion 34 It is connected with the tip of -1. Thus, the connecting portion 34B is formed.

  In this configuration, the first asterisk protrusion 34 and the second asterisk protrusion 36 are connected in a step-like manner from the inner side to the outer side in the tire radial direction via the connecting portions 34A and 34B.

  Further, in the first asterisk protrusion 34 and the second asterisk protrusion 36 adjacent in the tire radial direction and the tire circumferential direction, the distance between the center O1 and the center O2 (hereinafter referred to as “interval P1”) is 0.1 mm or more. It is considered to be a predetermined one value of not more than 0 mm. When the interval P1 is less than 0.1 mm, the formation of the projections becomes difficult. Furthermore, when the interval P1 becomes larger than 1.0 [mm], the incident light is attenuated and the lightness is lowered to such an extent that it appears black as compared to the other areas 20 other than the decorative part 14 in the tire side part 12 There is a risk that this will not be possible (details will be described later)

  As shown in FIG. 4, the height H1 of the first asterisk protrusion 34 and the height H1 of the second asterisk protrusion 36 respectively indicate the depth dimension D of the decorative portion 14 (the surface of the other region 20 of the tire side portion 12 Is preferably smaller than the dimension from the surface to the base surface 30). In other words, it is preferable that the first asterisk protrusion 34 and the second asterisk protrusion 36 do not protrude beyond the surface of the other region 20 of the tire side portion 12.

[Gradation area 48]
In the decorative portion 14 of the present embodiment, the lightness of the low lightness region 18 is not uniformly lowered as a whole (that is, the lightness value is not set to a constant value), and a width for expressing the decorative portion In order to widen the image, some parts have a gradation of lightness that makes it appear gradually brighter than black. Hereinafter, in the low lightness area 18, an area to which gradation is applied is referred to as a gradation area 48. As shown in FIG. 1, in the decorative portion 14 of the present embodiment, four band-like gradation regions 48 extending obliquely with respect to the tire circumferential direction are provided.

  As shown in FIG. 1B, in the low lightness area 18 of the present embodiment, rib-like bottom raising projections 50 are provided on the base surface 30 in order to provide the gradation area 48. The bottom raising projection 50 is an example of a bottom raising portion. The cross-sectional shape perpendicular to the longitudinal direction of the bottom raising projection 50 gradually decreases in height from the central highest ridge 50A toward both sides in the width direction. In other words, the heights of the bottom raising projections 50 gradually increase from the both widthwise ends (bottoms) 50C toward the ridge 50A. In the bottom raising projection 50, one side portion (half portion in the width direction) of the ridge 50A is an example of the gradual increase area. The slopes 50B located on both sides of the ridge 50A have a center of curvature outside the tire and are formed in a substantially arc-shaped surface that is convex toward the base surface 30. In other words, the inclination angle of the slope 50B with respect to the base surface 30 gradually increases from the widthwise end (bottom) 50C toward the ridge 50A.

  In the cross-sectional view perpendicular to the longitudinal direction of the bottom raising projection 50 on the left side shown in FIG. 1B and the enlarged plan view showing the lightness of the gradation area 48 of the low lightness area 18 on the right, The second asterisk projections 36 are omitted, and in the plan view on the right side, only the change in lightness is shown.

  The height H3 of the bottom raising projection 50 is smaller than the depth dimension D of the decoration 14 (see FIG. 4A), and the height H1 of the first asterisk projection 34 and the height H1 of the second asterisk projection 36 Preferably it is smaller than (see FIG. 4). The height H 3 of the bottom raising projection 50 in the present embodiment is constant in the longitudinal direction of the bottom raising projection 50. Although the width W of the bottom raising projection 50 is not particularly limited, as shown in FIG. 2, the half area 48A of 1/2 of the width direction of the gradation area 48 (a width of 1/2 of the width W of the bottom raising projection 50) ), A plurality of first asterisk projections 34 and second asterisk projections 36 may be disposed in the width direction (direction in which the height changes). The half area 48A is an example of the gradual reduction area.

  Here, in the base surface 30 of the gradation area 48 of the present embodiment, an area provided with the slope 50B from the ridge 50A to the width direction end (bottom) 50C, in other words, 1/1/1 of the width direction of the gradation area 48 The two half regions 48A correspond to the tapering regions as an example of the present invention. By providing slopes 50B on the base surface 30, the height (apparent height) Hf measured from the surface (surface of the slopes 50B) of the plurality of first asterisk protrusions 34 and second asterisk protrusions 36 from the surface of the bottom raising protrusion 50 Is gradually reduced from the ridge 50A to the slope 50B from the widthwise end (foot) 50C.

  Here, the low-lightness region 18 which looks black as described in the present embodiment is, for example, a region where the lightness L value measured using a handy type spectrocolorimeter of Nippon Denshoku Kogyo Co., Ltd. is less than 10 as an example. However, the value of the lightness L may not be less than 10 as long as it looks darker than the other areas 20 other than the decorative part 14.

  On the other hand, for the other region 20 (the region in which the first asterisk protrusion 34 and the second asterisk protrusion 36 are not formed) other than the decorative portion 14 in the tire side portion 12, handy type spectroscopy of Nippon Denshoku Kogyo Co., Ltd. The value of the lightness L measured using a color difference meter is, for example, an area larger than 20, but the lightness L may be 20 or less. That is, the low-lightness area 18 that appears black is an area on the outer surface of the tire 10 that is relatively low in lightness compared to the surroundings.

(Action, effect)
Next, the effects of the tire 10 according to the present embodiment will be described.
In the other area 20 where the first and second asterisk projections 34 and 36 of the tire side portion 12 are not formed, incident light is reflected outward by the outer surface constituting the other area 20.

  On the other hand, in the low brightness region 18 provided in the decorative portion 14 of the tire side portion 12, light incident on the first asterisk protrusion 34 and the second asterisk protrusion 36 formed in the low brightness region 18 is shown in FIG. It corresponds to the side 34D shown in. Then, the incident light is attenuated while being repeatedly reflected between the facing side surfaces 34D and then reflected outward.

  Thus, the amount of light reflected outward in the low brightness region 18 is compared to the amount of light reflected outward in the other regions 20 where the first and second asterisk protrusions 34 are not formed. As a result, the low lightness region 18 appears relatively black as compared to the other regions 20.

  Also, as shown in FIGS. 1 and 4, in the low lightness region 18, a gradation that changes the height Hf measured from the surfaces of the plurality of first asterisk protrusions 34 and the second raised protrusions 50 of the second asterisk protrusions 36. An area 48 is provided. The portion of the gradation region 48 where the first and second asterisk protrusions 34 and 36 having a relatively high height Hf are formed has a relatively small amount of light reflected to the outside and appears relatively black. In the portion where the low first asterisk protrusion 34 and the second asterisk protrusion 36 are formed, the amount of light reflected to the outside is relatively large, and it appears relatively bright.

  In the gradation region 48, since the height of the bottom raising projection 50 gradually changes, it looks brighter gradually from the lower portion to the high portion of the bottom raising projection 50. That is, since a smooth gradation is applied to the lightness in the gradation area 48, the width for expressing the decorative portion 14 can be expanded compared to the case where the lightness is constant (an increase in the number of methods). it can). In the low lightness region 18, the vicinity of the ridge 50A of the bottom raising projection 50 becomes relatively bright and noticeable.

  As shown in FIG. 3, the extension parts 34E of the first asterisk protrusions 34 extend in different directions, and the extension parts 36E of the second asterisk protrusions 36 extend in different directions. ing. As a result, even when the low lightness area 18 is viewed by changing the viewing angle with respect to the low lightness area 18, it is possible to suppress the difference in the appearance.

  In addition, the first asterisk protrusion 34 and the second asterisk protrusion 36 are connected in a step-like manner via the connection portions 34A and 34B. Thereby, the first asterisk protrusion 34 and the second asterisk protrusion 36 support each other through the connecting portions 34A, 34B, and the falling-down of the first asterisk protrusion 34 and the second asterisk protrusion 36 is suppressed to improve the durability. Can.

Second Embodiment
Next, an example of a tire according to a second embodiment of the present invention will be described according to FIGS. 5 and 6. The same components as those of the first embodiment are denoted by the same reference numerals, and the description thereof will be omitted.

  As shown in FIGS. 5 and 6, on the base surface 30 of the decorative portion 14 of the present embodiment, a plurality of rib-like protrusions are used instead of the first asterisk protrusion 34 and the second asterisk protrusion 36 of the first embodiment. 52 is provided. As shown in FIG. 5, the rib-like protrusions 52 are formed in a zigzag shape in a plan view of the decorative portion 14. The rib-like protrusion 52 is an example of a protrusion.

  As shown in FIG. 6, in the rib-like protrusion 52, the cross section in the direction orthogonal to the extending direction is substantially in the shape of an isosceles triangle having a flat top surface 52C. That is, the rib-like protrusion 52 has a top surface 52C and a pair of side surfaces 52D. In the present embodiment, the width (Wa in the figure) of the top surface 52C is 0.02 [mm], and the apex angle (Da in the figure) of the rib-like protrusion 52 is 26 [degree]. Further, the height (Ha in the figure) of the rib-like protrusion 52 measured from the base surface 30 is a predetermined one value of 0.1 mm or more and 1.0 mm or less.

  In the adjacent rib-like protrusions 52, the distance between the centers of one rib-like protrusion 52 and the center of the other rib-like protrusion 52 (hereinafter referred to as “distance Pa”) is 0.1 [mm] or more 1.0 [1.0 mm] is a predetermined one value below.

  The rib-like protrusions 52 provided in the low lightness region 18 of the decorative portion 14 of the present embodiment are different in shape from the first asterisk protrusions 34 and the second asterisk protrusions 36 of the first embodiment, but are similar to the first embodiment. According to the principle of (1), light incident on the rib-like projections 52 is attenuated while being repeatedly reflected between the facing side surfaces 52D and then reflected outward. Thus, the amount of light reflected to the outside in the low lightness region 18 of this embodiment is smaller than the amount of light reflected to the outside in the other regions 20 where the rib-like protrusions 52 are not formed. As a result, the low lightness region 18 looks relatively black as compared to the other regions 20.

  Also in the low lightness area 18 of the present embodiment, the gradation area 48 for gradually reducing the height measured from the surface of the bottom raising projection 50 of the rib-like projection 52 is provided, so the height is relatively high in the gradation area 48 The portion where the rib-like projections 52 are formed is relatively black with a small amount of light reflected to the outside, and is reflected outside when the rib-like projections 52 having a relatively low height are formed The amount of light is relatively large and appears relatively bright.

  Therefore, even in the low brightness region 18 of the present embodiment provided with rib-like protrusions 52 having a shape different from the first asterisk protrusion 34 and the second asterisk protrusion 36, it is possible to provide a smooth gradation in brightness in the gradation region 48. As compared with the case where the lightness is fixed, the width for representing the decorative portion 14 can be expanded (the method can be increased).

<Other Embodiments>
Although the present invention has been described in detail with respect to the specific embodiments, the present invention is not limited to the embodiments, and it is possible that other various embodiments are possible within the scope of the present invention. It is clear to the trader.

  For example, in the above embodiment, the inclination angle of the slope 50B of the bottom raising projection 50 is gradually increased from both ends toward the ridge 50A, but as shown in FIG. 7A, the inclination 50B has a constant inclination angle. It may be planar, and as shown in FIG. 7B, the slope 50B has a slope angle gradually decreasing from the both ends toward the ridge 50A, and has a concave curved surface toward the base surface 30. May be As shown in FIG. 1C, the slope 50B is formed into a substantially arc-shaped surface having a curvature center on the outer side of the tire and convex toward the base surface 30, as shown in FIG. 7 and the shape shown in FIG. 7 (B), the ridge 50A which is the maximum height of the bottom raising projection 50 can be clearly shown in appearance.

  Moreover, although the bottom raising projection 50 of embodiment mentioned above was provided with the slope 50B in the both sides of ridge 50A, as shown in FIG.7 (C), as for the bottom raising projection 50, only one side is the slope 50B. The other side may be a vertical plane perpendicular to the base surface 30.

  Although the height H3 of the bottom raising projection 50 is constant in the longitudinal direction of the bottom raising projection 50 in the above embodiment, the height H3 may be changed in the longitudinal direction. Thus, gradation can be applied in the longitudinal direction of the bottom raising projection 50 in the gradation area 48, and the width for expressing the decorative portion 14 can be further expanded.

  Although the width W of the bottom raising projection 50 is constant in the longitudinal direction of the bottom raising projection 50 in the above embodiment, the width W may be changed in the longitudinal direction. Thus, gradation can be applied in the longitudinal direction of the bottom raising projection 50 in the gradation area 48, and the width for expressing the decorative portion 14 can be further expanded.

  In the above embodiment, the bottom raising projections 50 are continuous in a rib shape, but may be formed intermittently.

  In the above embodiment, the bottom raising projection 50 is formed in a rib shape extending in one direction, but the present invention is not limited to this, and may be formed in a conical shape, for example. This makes it possible to make the gradation area 48 appear circular in plan view, and to make the lightness at the center of the circle have the highest lightness so that the lightness gradually decreases from the center toward the radial outside. it can.

  The shape of the gradation area 48 in plan view is not limited to the arc shape, and may be another shape such as a linear shape, and may be characters, a brand logo, a mark, and the like.

  In the above-described embodiment, the entire decorative portion 14 is the low brightness area 18, but only a part of the decorative portion 14 may be the low brightness area 18 (the rest is only the base surface 30). The shape when the low brightness region 18 is viewed in plan is not limited to the arc shape, and may be another shape such as a linear shape, and may be characters, a brand logo, a mark, and the like.

  Although the decorative portion 14 having the low brightness region 18 is provided in the tire side portion 12 of the tire 10 in the embodiment described above, the decorative portion 14 may be provided in the bead portion although not shown, for example, FIG. As shown in the drawing, the low lightness area 18 provided with the gradation area 48 may be provided at the groove bottom of the groove 56 formed in the tread 54, and the groove bottom may be a decorative portion. Although not shown, the low lightness region 18 may be provided on the groove side surface of the groove 56, and the groove side surface may be used as a decorative portion. That is, if it is the outer surface of the tire 10, the site | part which provides the decoration part 14 is not limited.

  For example, in the low lightness region 18 of the first embodiment, the bottom raised projection 50 is provided to change a valley depth between the projections in order to make a part of the low brightness region 18 a first projection 34 and the Although the height Hf from the bottom raising projection 50 of the two asterisk projections 36 was changed, the heights of the first asterisk projections 34 and the second asterisk projections 36 from the base surface 30 are gradually changed as shown in FIG. The above region can be defined as a gradation region 48, and a smooth gradation can be applied to the lightness to widen the width for representing the decorative portion 14 (the method can be increased).

DESCRIPTION OF SYMBOLS 10 tire 12 tire side 14 decoration part 18 low brightness area (an example of a pattern area) 30 base surface 34 1st asterisk protrusion (an example of protrusion) 36 2nd asterisk protrusion (An example of a projection) 48: gradation area 48A: half area (gradually decreasing area) 50: base raising projection (bottom raising part, gradually increasing part)

Claims (8)

A decorative portion formed on the outer surface of the tire and having a base surface;
The projection provided in the decorative portion and projecting from the base surface at a height of 0.1 mm or more and 1.0 mm or less is 1.0 mm larger than 0.1 mm. A plurality of pattern areas formed at intervals of
Equipped with
The tire according to claim 1, wherein the pattern area is provided with a gradually decreasing area in which the heights of the plurality of protrusions disposed adjacent to each other gradually decrease.   The plurality of projections are provided with the plurality of projections having a constant height from the base surface in the gradually decreasing area, and a plurality of raised portions having a gradually increasing portion whose height from the base surface is gradually increased. The tire according to claim 1, wherein the height from the bottom raising portion to the top of the protrusion is gradually reduced by being provided across the two.   The tire according to claim 2, wherein in the bottom raising portion, the two increasing portions are connected in opposite directions to each other.   The tire according to claim 2 or 3, wherein the portion where the height of the bottom raising portion changes is formed by a curve that is convex toward the base surface. The base surface is a bottom of a recess formed toward the tire inner side than the outer surface,
The tire according to any one of claims 2 to 4, wherein the raised bottom portion is formed such that a top portion does not protrude from the outer surface to the outside of the tire. The base surface is a bottom of a recess formed toward the tire inner side than the outer surface,
The tire according to any one of claims 2 to 4, wherein the projection is formed such that a top does not project outward from the outer surface of the tire.   The tire according to any one of claims 1 to 6, wherein the height of the protrusion measured from the base surface is constant in the gradual decrease region.   The tire according to claim 2, wherein the tapering area is provided with three or more types of the projections having different heights from the bottom raising portion.